Metallurgical process.



W. MoA. JOHNSON. METALLURGICAL PROCESS. APPLICATION FILED SEPT. 20,1909.

1,107,81U Patented Aug.18,1914. I 2 SHEETS-SHEET 1.

WITNESSES:

' W. McA. JOHNSON.

METALLURGICAL PROCESS.

APPLICATION FILED SEPT. 20,1909.

' Patented Aug.

2 SHEETS- Lmmmm W U I WITNESSES:

WOOLSEY MoA. JOHNSON, OF HARTFORD, CONNECTICUT.

METALLURGICAL PROCESS.

Specification of Letters Patent. 1 Patented A g 18, 1914 Application filed September 20, 1909. Serial No. 518,530.

To all tvhowt it may concern:

Be it known that I, WOOLSEY MQA. J OHN- SON, a citizen of the United States, resid-' ing at Hartford, in the county of Hartford and State 'of Connecticut, have invented certain new and useful Improvements in Metallurgical Processes, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention deals broadly with a metallurgical rocess whereby an ore rich in a metalloid such as arsenic as well as either nickel or cobalt and perhaps other valuable constituents may be commercially treated so as to enable its various constituents to be readily separated and otherwise refined. Inasmuch, however, as many ofthe noteworthy advantages characteristic of this invention prominently appear in its more intense aspect as a metallurgical process especially applicable to the treatment of the extremely valuable and yet very intractable ores of the Temiskaming region, some of which contain around about 35% arsenic, 10% cobalt, 5% nickel, 10% silver and a valueless residue containing silica and some carbonates, as of calcium, it will be conducive to clearness to disclose the invention by way of a detailed discussion of such an embodiment thereof.

t The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplified in the construction herecation of which will be indicated in lowing claims. 4

inafter set forth, and the scope of theappli the fol In'order that this invention may be more" 'readi'ly'disclosed and rendered comprehensible to those skilled in this art, drawings exemplifying two forms of apparatus suitable for acting as a means instrumental incarrying out this process are shown, and in such drawings:

Figure '1 shows a horizontal furnace or retort for the "chloridizing operation, in which the ore is reacted upon'whlle in a quiescent state; Fig. '2 is a form of'tower which may be employed for thechloridizing operation and in which the ore, while rapidly fallinglthrough' the tower in the form of a shower and while thus in a state of movement is nevertheless" in a condition capable of precluding granular agglomeraaction of some such agent as hydrochloric acid in aqueous solution so that the contained lime may be brought into solution and thus separated out, leaving an undissolved residue which may then be subjected to the following step of my process, or mechanical concentration on be employed. v

In order to adequately comprehend the commercial importance of the next step of my process, it may here be noted that it is of the utmost consequence'that the various steps or stages of any process, particularly when formulated for the purpose of' commercially refining ores displaying the perplexing metallurgical obstinacy characteristic of ores of the Temiskaming region,

shall be selected or devised with a more.

terial or residueto be subsequently treatedinsuch physical and chemical condition that Wilfley table's may the'fsucceedingn steps of the process may be 7 not only readily carried out'but, also, that suchsteps per '86 may be comparatively simple and essentially practicable from a e'hemical or metallurgical standpoint. Take,

for" example, an one such as that under "present consideration, it is perhaps possible to devise a process which will serve to efficiently extract silver contents by means of certain individual steps which may be comparatively simple and yet such a process may have the very serious objection of leavin residues containing, say, nickel and ooha t in such physical and chemical form as W to render the complete separation or purification oftgese valuable ingredientsextremely diflic lt if not commerciallyimpracticable.

It is, therefore, a primary object of this invention to so'fdevise and relate the various steps of my process as'to maintain or procure'not only simplicity and efiectiveness in the steps per se, but, also, a commercially efiicient and metallurgically harmonious relationship between such steps so that they will all eo-act to the best advantage.

This invention, therefore, proposes as an early step of my process, the utilization of a gaseous chloridizing agent, such, for instance, as moist chlorin gas. In carrying out this stage of my process, the ore or residue containing high percentages of arsenic, silver, nickel and cobalt will be first obtained in a granulated or comminuted condition and then, while at a temperature varying from 250 C. to 350 C. and in what may be termed a precluding granular agglomeration state, subjected for a period of time varying from'ninety minutes to three hours, to the action of moist chloringas in the presence of aqueous vapor. As a result of my extensive investigations, I have discovered that eflieiency and acceleratlon of ac-' tion is greatly promoted by maintaining the. above mentioned conditions, 2'. 6., using wet chlorin gas in connection with ore handled in such manner as to prevent or avoid the violent collision of particles, which would tend to cause cohesion of the granules. By this term granular non-agglomeration as employed in my specification and claims, I, therefore, mean an ore either contained in a suitable vessel or on shelves in a quiescent state,as well as ore inisuch a state of movement such as that obtained by permitting the ore to fall through a tower such as thatLshown in the annexed drawings, which movement will not tend to repeatedly rub or roll the particles together and cause granular cohesion, as contradistinguished from the ordinary rotating or tumbling .methods, or mechanically rabbled furnaces, so frequently employed in connection with metallurgical roasting.

I have ascertained that when ,an ore of the specific character herein mentioned is subjected to the action of chlorin gas at a temperature ofabout 350 C. and upward, that the surfaces of the particles of such ore are in a more or less pasty condition and the effect of tumbling or rolling such ore is to cause the various particles thereof to cohere and agglomerate to such an extent as to not only interfere with the complete chloridization of the ore and the volatilization of the arsenic but, also, to cause such ore to cling to the sides of the roasting vessel and be otherwise brought into a. condition unadapted for subsequent handling and treatment.

In ehloridizing the ore or residue it is preferable to pass the chlorin gas through a tube having its end terminating below the surface of a body of water contained in a transparent receptacle, so that the chlorin may not only be suitably moistened but its flow readily'observed by the rate at which.

it bubbles up through the water. By observing the outlet from the roasting and chloridizing chambers the operator will-be enabled to note whether or not excess of chlorin is passing through the apparatus. I have found, however, that the chlorin acts very completely and ener etically on the ore,

not only quickly chlori izing the directly exposed surface of the ore but extending into the interior portions thereof with great ease apparently by virtue of a sort of catalytic or carrier action. The reaction being exothermic in nature, the temperature tends to rise rapidly beyond that which my discoveries have set as roper limits below which a consequential amount of silver chlorid may volatilize and an undesirable agglomeration of the ore may take place,

and I" therefore have adopted the'herein de-' scribed step and means for maintaining the proper working temperature, which is about 350 C.

An embodiment of an apparatus suitable as a means instrumental in subjecting the ore to the action of moist chlorin gas at a carefully controlled predetermined temperature is diagrammatically illustrated by Fig.

1. Such apparatus consists of a furnace A containing a plurality of retorts B. This furnace A may be constructed of suitable heat resisting material, such as fire-brick or the like, and may provide a retort chamber 1 formed by the side walls 2, the arch 3, and the floor 4. The arch 3 and the floor 4 will preferably provide a number of vents or flues 5 and 6, respectively, to enable the temperature controlling air or gases to be brought into intimate .contact with the walls of the retorts. To this end, the furn'ace'A will preferably provide a wall 7 arranged to leave a space 8, which serves as a conduit for the entering, heat controlling air, and in like manner awall 9 is arranged to form a conduit 10 for the discharge of the heat controlling gases.- The retorts B may be su1tably shaped, as forinstance in the form of an ordinary mufile, and will each contain one or more perforated trays 11 supported on suitablev blocks 12, or otherwise. These perforated trays are to be covered. with ore, then placed in the retorts and the latter very carefully sealed up so as to prevent any escape ofthe poisonous arsenic chlorid. At

13 is shown a'pipe serving as a conduit for admitting the moist chlorin gas to the first retort; next one of the series by means of a condult 14 of fire-clay or the like, and in like manner the successive retorts of the series are connectedtogether, the last one being connected with thepipe 15 through which the gaseous arsenic chlorid is withdrawn from the system. In this connection it should be observed that-the entire system is preferably arranged to work under a slight negative This retort is connected with the pressure by using suction-pumps or the like crevices or the like in the roasting furnace and possibly produce injury to the workmen.

Fig. 2 illustrates an embodiment of an apparatus also designed to serve as a means instrumental in efficiently chloridizing the ore. Such apparatus consists of a tower C constructed of suitable heat resisting material, as of fire-brick. The circular or otherwise contoured wall of said tower preferably contains one or more continuous passageways 20 arranged on the inner surface of the wall and through which the heat controlling gases may be passed so as to keep the temperature within proper limits. At the top of this tower some suitable ore delivering apparatus is arranged, such as, for example, a hopper 21 having a perforated bottom' 22 (which may be of about 100 mesh) and mounted on springs 23 so as to be capable of agitation. A rotatingmam 2 lis suitably arranged to agitate the hopper 21. Preferably, this hopper is so arranged. as, by means of a plate 25, to maintain a cl osi-ire of the opening and thus prevent the escape of arsenic chlorid. The ore sifted through the bottom of the hopper falls through the central chimney-like w'ayof the tower until it reaches the bottom 26, which is so constructed as to enable it to be withdrawn. This ore will be preferably of one hundred mesh, so as to enable the chlorin gas to have a complete action. At the bottom of the tower there are provided one or more conduits 27 through which is admitted moist hot chlorin gas and, preferably, the ore itself is maintained at as high a temperature as may be practical, so as to prevent any chilling effect and enable the reaction to be car ried out immediately. The temperature at which the interior of the tower is to be I maintained is approximately 350 C. It has been ascertained by experiment that the ore in thus falling through a tower of a height of, say, fifteen or twenty feet.is completely chloridized and gaseous arsenic chlorid may be withdrawn from the upper part of the tower through the conduit 28. The chlorin gas thus acting on the ore transforms its constituents to chlorids, leaving a porous, granulated like residue each particle of which issomewhat puffed out. The arsenic, however, has'been changed to arsenic-chlorid AsCl which is a heavy, yellowish liquid having a-speoific gravity of 2.6 and which because of the fact that its boiling point is at atmospheric pressure (136 C.) will pass off as a vapor. This vapor is, of course, ex-

, ceedingly' poisonous and, therefore, I have is preferably passed into a chilling room where it is subjected to the action of jet condensers, or surface condensers, and enabled to re-act with water so as to be transformed into the insoluble arsenious acid As,O which is filter pressed and removed as a by-product. The reaction is assumed to be as follows:

The porous, granular residue is withdrawn from the chloridizing tubing or chamber when the arsenic contained therein has been expelled in the manner above indicated and will now be found to be in a condition admirably adapted for further treatments aiming particularly toward the isolation in com;- mercially desired forms of the remaining valuable constituents of such residue. For

example, it will be found that such ingredients have been all transformed into chlorids which, with the exception of the silver chlorids, are readily soluble in slightly acidulated water. Therefore, as the next step of my process, this porous, granular residue containing very high percentages of silver, nickel and cobalt may be leached with Water acidified with from to 5% er hydrochloric acid. The valuable ingredinickel chlorid NiCl and cobalt chlorid.

The iron may very conveniently and 'efliciently be separated out by first transforming the same from the ferrous to the ferric condition by introducing enough chlorin gas into the solution to oxidize the iron to FeCl and then milk of lime may be added and the solution agitated'so as to precipitate the iron in the form of ferric hydrate Fe (0H),. The filterate from the above mentioned iron hydrate avill now contain all of the nickel and cobalt and these two substances may beseparated by known methods, as oxychlorid of lime or by chlorin gas and soda ash.

The residue from the chloridizing operation, as has been observed, contains silver chlorid and is thus well adapted for subsequent treatment whereby the silver may be from the potassium silver cyanid solution by means of zinc or aluminum shavings in the usual manner. v

Viewed in the light of current knowledge and without the necessity of further elaboration, the foregoing disclosure will be sufficiently suggestive and otherwise enable those skilled in the art to easily devise certain interchangeably available embodiments and utilizations of'this invention which, al-

though perhaps calculated to seem dissimilar, and possibly performed by means of apparatus differing considerably in detail and appearance from that herein shown, would nevertheless involve the ideas and utilities which, from the aspect from the prior art, are characteristic of the spirit of this invention and which, therefore, should and accordingly are intended to fall within the contemplation of the following claims. I, therefore, desire that all matter the foregoing disclosure shall be interpreted as purely illustrative and not in a limiting sense, as it will be clear that the various steps and operations herein described may be identified by the use of various more or less arbitrary terms and that the terminology employed is descriptive rather than limiting.

Having thus amply disclosed my invention, What I claim as new and desire to secure by Letters Patent of the United States 1. A process of the nature disclosed for treating ores containing among other metallic constituents silver and large amounts of arsenic, consisting in subjecting the'comminuted ore in a closed vessel to the action of moist chlorin gas at an elevated temperature, collecting the evolved vapors of arsenic chlorid and thus obtaining a residue free from arsenic, and then treating said residue to effect a separation of its valuable eonstituents.

, ,2. A process of thenature disclosed for treating ores containing among other metallic constituents silver, nickel and arsenic, consisting in subjecting the comminuted ore to the action of moist chlorin gas at an elevated temperature, withdrawing the evolved arsenic chlorid from said vessel until the arsenic has been substantially removed from the residue, then leaching said residue, treating the insoluble matter to separate the silver therefrom, and treating the solution to separate the nickel therefrom.

3. A process of the nature disclosed for treating ores containing among other metallic constituents nickel, cobalt and arsenic, consisting in subjecting said ores in comminuted form to the action of moist chlorin gas for a period sufficient to convert substantially all the arsenic to arsenic chlorid, separating the vapors of arsenic chlorid from the residue, and then treating said residue to efl'ect an isolation of the nickel and the cobalt contained therein.

4. A process of the nature disclosed for treating ores containing silver, nickel, cobalt and arsenic, consisting in subjecting the comminuted ore to the action of moist chlorin gas for a time sufficient to convert substantially all of the arsenic to arsenic chlorid, separating the gaseous arsenic chlorid from the residue, leaching said residue to bring the nickel and cobalt compounds into solution, treating said solution to separate the nickel fr m the cobalt, and treating the insoluble silver-containing residue to separate the silver therefrom.

5. A process of the nature disclosed for treating ores containing among other metallic constituents nickel and considerable amounts of arsenic, consisting in subjecting the comminuted ore in a closed vessel to the action of moist chlorin gas at an elevated temperature, withdrawing the evolved vapors of arsenic chlorid and thus obtaining a residuefree from arsenic, then-leaching said residue to obtain a solution containing a compound of nickel, and then treating said solution to obtain metallic nickeLthere from.

6. A process of the nature disclosed for treating ores containing among other metallic constituents nickel and considerable amounts of arsenic, consisting in subjecting the comminuted ore in a closed vessel to the action of moist chlorin gas at a temperature of approximately 350 0., extracting excess quantities of heat engendered by said exothermic reaction to maintain the temperature as aforesaid, withdrawing the evolved vapors ofarsenic chlorid, and then treating the residue to separate the nickel therefrom.

7. A' process of the nature disclosed for treating ores containing among other metallic constituents silver and large amounts of arsenic, consisting in subjecting the comminuted ore in" a closed vessel to the action of moist chlorin gas at an elevated temperature, extracting excess heat engendered by said exothermic action to maintain the temperature at approximately 350 C., withdrawing the evolved vapors of arsenic chlorid and thus obtaining a residue free from arsenic, and then treating said residue to effect a separation of its valuable constituents. I

8. A process of the nature disclosed for treating ores containing among other metallic constituents silver, nickel, and arsenic, consisting in subjecting the comminuted ore to the action of moist chlorin gas at an elevated temperature, extracting the excess heat engendered by said exothermic reaction to maintain the temperature at approximately 350 (1, withdrawing the evolved arsenic chlorid from said vessel until the arsenic has been substantially removed from the residue, then leaching said residue, treating the insoluble matter to separate the silver therefrom, and treating the solution to separate the nickel therefrom.

9. A process of the nature disclosed'for treating ores containing among other nietallic constituents nickel, cobalt, and arsenic, consisting in subjecting said ores in comminuted form to the action of moist chlorin gas at an elevatedtemperature, extracting the excess heat engendered by said exotherllllO reaction to maintain the temperature at approximately 350 (1, separating the vapors of arsenic chlorid from the residue, and then treating said residue to effect an isolation of the nickel and cobalt contained therein.

10. A process of the nature disclosed for treating ores containing silver, nickel, cobalt and arsenic, consisting in subjecting the connninuted ore to the action of moist chlorin gas at an elevated temperature, extracting excess heat engendered by said exothermic reaction to maintain the temperature at approximately 850 0., separating the gaseous arsenic chlorid from the residue, leaching said residue to bring the nickel and cobalt compound to solution, treating said solution to separate the nickel from the co-. balt, and treating the insoluble silver containing residue to separate the silver therefrom.

11. A process of the nature disclosed for "treating ores containing among other metallic constituents nlckel and large amounts of arsenic, consisting in subjecting the comminuted ore in a closed vessel to the action of moist chlorin gas at an elevated temperature, maintaining a pressure less than atmospheric of gas within said closed vessel toprevent any uncontrollable escape of va-' pors' of arsenic chlorid, withdrawing the evolved vapors of arsenic chlorid and thus obtaining a residue free from arsenic, and then treating said residue to obtain the nickel therefrom. 12. A process of the nature disclosed for treating ores containing among other metallic constituents silver and large amounts of arsenic, consisting in subjecting the comminuted ore in a closed vessel to the action of moist chlorin gas at an, elevated temperature, maintaining the gases within said vessel at a pressure less than atmospheric to prevent the uncontrollable escape of vapors of arsenic chlorid, withdrawing the evolved vapors of arsenic chlorid from said vessel and thus obtaining a residue free from arsenic, and then treating said arsenic to obtain a separation of its valuable constituents.

' 13. A' process of the nature disclosed for treating ores containing among other metallic constituents silver, nickel, and arsenic,

to the action of moist chlorin gas at an elevated temperature, maintaining a pressure less than atmospheric in the vessel containing said ore to prevent any uncontrollable escape of gases therefrom, Withdrawing the evolved arsenic chlorid from said vessel until the arsenic has been substantially re-.

moved from the residue, then leaching said residue, treating the insoluble matter to separate the silver therefrom, and treating the solution to separate the nickel therefrom.

14. A process of the nature disclosed for treating ores containing among other metallic constituents nickel, cobalt and arsenic, consisting-in subjecting said ores in comminuted form to the action of moist chlorin gas for a period sufiicient to convert substantially all the arsenic to arsenic chlorid, maintaining a pressure less than atmospheric in the vessel containing said ores to prevent any uncontrollable escape of gases, withdrawing the gaseous. arsenic chlorid from the residue, and then treating said residue to effect an isolation of the nickel and cobalt contained therein.

15. A process of the nature disclosed for treating ores containing silver, nickel, cobalt and arsenic, consisting in subjecting the comminuted ore to the action of-I'noist chlorin gas for a time suflicient to convert substantially all of the arsenic to arsenic chlorid, maintaining a a pressure less than atmospheric within the vessel containing said ores to prevent any uncontrollable escape of gases therefrom, withdrawing the gaseous arsenic chlorid from the residue, leaching said residue to bring the nickel and cobalt compound into solution, treating said solution to separate the nickel from the cobalt, and treatingthe insoluble silver-containing residue to separate the nickel therefrom.

16. A process of the nature disclosed for treating ores containing among other metallic constituents silver and large amounts of arsenic, consisting in subjecting the comminuted ore at an elevated temperature and in a state precluding granular agglomeration to the action of moist chlorin gas, withdrawing the evolved vapors of arsenic chlorid and thus obtaining a residue free from arsenic, and then treating said residue to effect a separation of its valuable constituents.

In testimony whereof I aflix my signature, in' the presence of two witnesses.

CHARLES M. STARKWEATHER, HARRY H. HOWARD. 

